diff --git a/Cargo.lock b/Cargo.lock
index 8b4aeb3..e1353ab 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -331,7 +331,7 @@ dependencies = [
 
 [[package]]
 name = "decomp-toolkit"
-version = "0.5.1"
+version = "0.5.2"
 dependencies = [
  "anyhow",
  "ar",
diff --git a/Cargo.toml b/Cargo.toml
index 1a544f8..4870da9 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -3,7 +3,7 @@ name = "decomp-toolkit"
 description = "Yet another GameCube/Wii decompilation toolkit."
 authors = ["Luke Street <luke@street.dev>"]
 license = "MIT OR Apache-2.0"
-version = "0.5.1"
+version = "0.5.2"
 edition = "2021"
 publish = false
 build = "build.rs"
diff --git a/src/cmd/dol.rs b/src/cmd/dol.rs
index d45c987..a8ac2db 100644
--- a/src/cmd/dol.rs
+++ b/src/cmd/dol.rs
@@ -142,6 +142,12 @@ pub struct ConfigArgs {
 #[inline]
 fn bool_true() -> bool { true }
 
+#[inline]
+fn is_true(b: &bool) -> bool { *b }
+
+#[inline]
+fn is_default<T: Default + PartialEq>(t: &T) -> bool { t == &T::default() }
+
 mod path_slash_serde {
     use std::path::PathBuf;
 
@@ -187,51 +193,56 @@ mod path_slash_serde_option {
 pub struct ProjectConfig {
     #[serde(flatten)]
     pub base: ModuleConfig,
-    #[serde(with = "path_slash_serde_option", default)]
+    #[serde(with = "path_slash_serde_option", default, skip_serializing_if = "is_default")]
     pub selfile: Option<PathBuf>,
+    #[serde(skip_serializing_if = "is_default")]
     pub selfile_hash: Option<String>,
     /// Version of the MW `.comment` section format.
     /// If not present, no `.comment` sections will be written.
+    #[serde(skip_serializing_if = "is_default")]
     pub mw_comment_version: Option<u8>,
     /// Disables some time-consuming analysis passes.
     /// Useful when the symbols file is already created.
-    #[serde(default)]
+    #[serde(default, skip_serializing_if = "is_default")]
     pub quick_analysis: bool,
-    #[serde(default)]
+    #[serde(default, skip_serializing_if = "is_default")]
     pub modules: Vec<ModuleConfig>,
     // Analysis options
-    #[serde(default = "bool_true")]
+    #[serde(default = "bool_true", skip_serializing_if = "is_true")]
     pub detect_objects: bool,
-    #[serde(default = "bool_true")]
+    #[serde(default = "bool_true", skip_serializing_if = "is_true")]
     pub detect_strings: bool,
-    #[serde(default = "bool_true")]
+    #[serde(default = "bool_true", skip_serializing_if = "is_true")]
     pub write_asm: bool,
     /// Specifies the start of the common BSS section.
+    #[serde(skip_serializing_if = "is_default")]
     pub common_start: Option<u32>,
     /// Disables all analysis passes that yield new symbols,
     /// and instead assumes that all symbols are known.
-    #[serde(default)]
+    #[serde(default, skip_serializing_if = "is_default")]
     pub symbols_known: bool,
     /// Fills gaps between symbols with
-    #[serde(default = "bool_true")]
+    #[serde(default = "bool_true", skip_serializing_if = "is_true")]
     pub fill_gaps: bool,
 }
 
-#[derive(Serialize, Deserialize, Debug, Clone)]
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq)]
 pub struct ModuleConfig {
     /// Object name. If not specified, the file name without extension will be used.
+    #[serde(skip_serializing_if = "is_default")]
     pub name: Option<String>,
     #[serde(with = "path_slash_serde")]
     pub object: PathBuf,
+    #[serde(skip_serializing_if = "is_default")]
     pub hash: Option<String>,
-    #[serde(with = "path_slash_serde_option", default)]
+    #[serde(with = "path_slash_serde_option", default, skip_serializing_if = "is_default")]
     pub splits: Option<PathBuf>,
-    #[serde(with = "path_slash_serde_option", default)]
+    #[serde(with = "path_slash_serde_option", default, skip_serializing_if = "is_default")]
     pub symbols: Option<PathBuf>,
-    #[serde(with = "path_slash_serde_option", default)]
+    #[serde(with = "path_slash_serde_option", default, skip_serializing_if = "is_default")]
     pub map: Option<PathBuf>,
     /// Forces the given symbols to be active in the linker script.
-    #[serde(default)]
+    #[serde(default, skip_serializing_if = "is_default")]
     pub force_active: Vec<String>,
 }
 
@@ -262,6 +273,8 @@ pub struct OutputUnit {
     pub object: PathBuf,
     pub name: String,
     pub autogenerated: bool,
+    pub code_size: u32,
+    pub data_size: u32,
 }
 
 #[derive(Serialize, Deserialize, Debug, Clone, Default)]
@@ -797,6 +810,8 @@ fn split_write_obj(
             object: out_path.clone(),
             name: unit.name.clone(),
             autogenerated: unit.autogenerated,
+            code_size: split_obj.code_size(),
+            data_size: split_obj.data_size(),
         });
         if let Some(parent) = out_path.parent() {
             DirBuilder::new().recursive(true).create(parent)?;
diff --git a/src/obj/mod.rs b/src/obj/mod.rs
index 462ecd1..fb3750d 100644
--- a/src/obj/mod.rs
+++ b/src/obj/mod.rs
@@ -293,4 +293,29 @@ impl ObjInfo {
             .filter(|(_, _, _, split)| split.unit == unit)
             .all(|(_, _, _, split)| split.autogenerated)
     }
+
+    /// Calculate the total size of all code sections.
+    pub fn code_size(&self) -> u32 {
+        self.sections
+            .iter()
+            .filter(|(_, section)| section.kind == ObjSectionKind::Code)
+            .map(|(_, section)| section.size as u32)
+            .sum()
+    }
+
+    /// Calculate the total size of all data sections, including common BSS symbols.
+    pub fn data_size(&self) -> u32 {
+        self.sections
+            .iter()
+            .filter(|(_, section)| section.kind != ObjSectionKind::Code)
+            .map(|(_, section)| section.size as u32)
+            .chain(
+                // Include common symbols
+                self.symbols
+                    .iter()
+                    .filter(|&symbol| symbol.flags.is_common())
+                    .map(|s| s.size as u32),
+            )
+            .sum()
+    }
 }